In a semiconductor manufacturing process, a plasma processing apparatus configured to perform a plasma process for the purpose of thin film deposition, etching, or the like is widely utilized. Examples of such plasma processing apparatus include a plasma CVD (Chemical Vapor Deposition) apparatus configured to perform a thin film deposition process, a plasma etching apparatus configured to perform an etching process, etc.
The plasma processing apparatus includes a processing chamber in which a plasma processing space is formed; a mounting table configured to mount thereon a processing target substrate within the processing chamber; and a gas supply system configured to introduce a processing gas for a plasma reaction into a processing chamber, etc. Further, in order to excite the processing gas within the processing chamber into plasma, the plasma processing apparatus also includes a plasma generating device configured to supply electromagnetic energy such as a microwave or a RF wave; and a bias voltage applying device configured to apply a bias voltage to the mounting table and accelerate ions in the plasma toward the processing target substrate mounted on the mounting table.
In the plasma processing apparatus, however, since the accelerated ions in the plasma collide with the processing target substrate, the temperature of the processing target substrate may be increased. In order to suppress such a temperature increase, it is known that a coolant flows within the mounting table. For example, it is disclosed in Patent Document 1 that coolant paths are formed in a region within the mounting table corresponding to a central portion of the processing target substrate and in a region within the mounting table corresponding to a periphery portion of the processing target substrate, respectively, and a temperature distribution of the mounting table is controlled by controlling a flow rate of the coolant flown into each coolant path.    Patent Document 1: Japanese Patent Laid-open Publication No. 2006-286733
In the prior art, however, it is not considered to perform the temperature control promptly with a simple configuration. That is, in the prior art, since a multiple number of opening/closing valves are provided at coolant paths connecting a chiller unit for cooling the coolant and the coolant paths within the mounting table and the temperature distribution of the mounting table is controlled by controlling ON/OFF operations of the opening/closing valves, the configuration of the apparatus may be complicated. Further, in the prior art, since a heating unit for heating the coolant is provided in addition to the chiller unit and the temperature is controlled while heating a part of the cooled coolant in the heating unit, it would take a relatively longer time to complete the temperature control.